Fix nullable bound on DataFetcherResult.newResult

[exijn]

Summary:

• Adds the missing nullable generic bound to the zero-argument DataFetcherResult.newResult() factory method.
• Allows Kotlin callers under JSpecify null-marked semantics to use nullable result types.
• Adds a regression source for Kotlin nullable type interoperability.

Problem:

• DataFetcherResult and its Builder allow nullable type parameters.
• The zero-argument newResult() method declared an unbounded T.
• Kotlin therefore interpreted the factory method type parameter as non-null and rejected nullable types.

Testing:

• ./gradlew compileTestKotlin failed before the Java change with Type argument is not within its bounds for DataFetcherResult.newResult<String?>().
• ./gradlew compileTestKotlin passed after the change.
• ./gradlew test --tests graphql.execution.DataFetcherResultTest passed: 26 tests.
• ./gradlew check -x test -x testng passed.
• ./gradlew javadoc passed.
• ./gradlew testng passed: 190 tests.
• ./gradlew test was run locally on Windows and failed in unrelated graphql.parser.MultiSourceReaderTest.can combine files; the failure reproduces when that test is run alone and appears tied to local checkout line endings for src/test/resources/multisource/a.txt (w/crlf).

Issue:
Fixes #4364

[github-actions]

Test Report

Test Results

Java Version	Total	Passed	Failed	Errors	Skipped
Java 11	5927 (±0)	5871 (±0)	0 (±0)	0 (±0)	56 (±0)
Java 17	5927 (±0)	5870 (±0)	0 (±0)	0 (±0)	57 (±0)
Java 21	5927 (±0)	5870 (±0)	0 (±0)	0 (±0)	57 (±0)
Java 25	5927 (±0)	5870 (±0)	0 (±0)	0 (±0)	57 (±0)
jcstress	32 (±0)	32 (±0)	0 (±0)	0 (±0)	0 (±0)
Total	23740 (±0)	23513 (±0)	0 (±0)	0 (±0)	227 (±0)

Code Coverage (Java 25)

Metric	Covered	Missed	Coverage	vs Master
Lines	30047	3121	90.6%	±0.0%
Branches	8785	1519	85.3%	±0.0%
Methods	8026	1206	86.9%	±0.0%

No per-class coverage changes detected.

Full HTML report: build artifact jacoco-html-report

Updated: 2026-08-13 23:48:57 UTC